[Two biotin-labeled probes of gentamicin resistance genes].

A 2.0 kb BamHI-HindIII fragment of pDG0103 from Australia containing gentamicin 2"-o-adenylytransferase [ANT(2")] gene and a 4.9 kb PstI-EcoRI fragment of pBY102 were recovered from low-temperature-melting agarose by the slot method. Both fragments were labeled with biotin-7-dATP by nick translation with a commercial kit. The result of colony and Southern hybridization was that: the 2.0 kb probe from Australia hybridized with that containing ANT(2") from America, while no hybridization occurred between the 2.0 kb probe and the 4.9 kb probe constructed in our lab. Furthermore, the above two fragments were used as probes for detection of 106 strains of gentamicin resistant Enterobacteriaceae. It revealed that there were more than one gentamicin resistance gene in the tested strains.